Bioassay for the early detection of autoimmune diseases

Abstract

Provided are methods for aiding in diagnosing autoimmune diseases in a mammal, comprising contacting a biological sample that is not a tear sample from the mammal with an antibody that specifically binds to a first polypeptide selected from the group Ctss, Ctsh, Ctsr, Ctsw, Ctsz, Ifng, IL-6ra, IL-10, IL-10ra, IL-15, Tnfa, Apo-F, or Lcn-2 or a second polypeptide selected from the group lactoperoxidase, lactoferrin or lysozyme under conditions favoring the formation of an antibody-polypeptide complex, and determining the amount of complex formed, wherein an increased formation of antibody-first-polypeptide complex or a decreased formation of antibody-second-polypeptide complex as compared to a suitable control, indicates a likely positive diagnosis of an autoimmune disease for the mammal, thereby aiding in the diagnosis. Methods of treating the autoimmune diseases are also provided.

The invention claimed is: 
     
       1. A method for detecting a polypeptide in a mammal likely to develop lupus or Sjogren's Syndrome, the method comprising the steps of:
 measuring an expression level of the polypeptide selected from the group consisting of cathepsin S (Ctss), cathepsin H (Ctsh), cathepsin R (Ctsr), cathepsin W (Ctsw) or cathepsin Z (Ctsz) by contacting a sample selected from the group consisting of saliva, plasma, blood, spinal fluid or lymphatic drainage with a Schirmer's test strip embedded with a quantitative fluorometric antibody specific for the polypeptide and measuring the amount of antibody bound to the polypeptide. 
 
     
     
       2. The method of  claim 1 , wherein the sample comprises saliva. 
     
     
       3. The method of  claim 1 , wherein the polypeptide is cathepsin S (Ctss). 
     
     
       4. The method of  claim 1 , further comprising administering to the mammal likely to develop lupus or Sjogren's Syndrome an effective amount of a suitable therapy. 
     
     
       5. The method of  claim 4 , wherein the suitable therapy is selected from the group consisting of a salivary flow-stimulating prescription drug, a nonsteroidal anti-inflammatory drug, disease-modifying antirheumatic drug, a monoclonal antibody, punctal plugs, a cathepsin inhibitor, or any combination thereof. 
     
     
       6. The method of  claim 1 , wherein the mammal is a human patient. 
     
     
       7. The method of  claim 1 , wherein the sample is saliva.